Improving the drying performance of parchment coffee due to the newly redesigned drying chamber

Abstract

AbstractThe Colombian coffee growers face many complications when using traditional open‐sun drying techniques such as post‐harvest process delays or incomplete grain dryness because of climate conditions. Therefore, local workshops began fabricating low‐capacity dryers simulating the industrial equipment working principles. One of the most commercialized units is a triple tray rectangular‐shaped dryer with a 31.25 kg capacity of dry parchment coffee per batch, providing the issue with an acceptable solution. However, it was redesigned into a circular shape holding a lower grain bed thickness and a vertical air inlet with a diffusive tray. Both units were simulated using the Thompson and the Michigan State University grain drying mathematical models to obtain their theoretical drying time. Then, a computational fluid dynamics simulation was conducted, attaining the unit's drying air behavior, the circular dryer exhibited notable drying times reduction and even air distribution, optimizing the dryer's performance, representing a benefit for the coffee‐growing farmers.Practical ApplicationsA cylindrical arranged coffee dryer with a vertical air inlet reduces the drying time of the grain, allowing a better rentability of the grower and improves the air distribution inside the equipment, meaning that the moisture removal will occur uniformly, safeguarding that the product's final moisture content meets the required conditions for safe storage.